Pollen allergen-Major Histocompatibility Complex class II complex (pMHC-II)

Pollen-derived proteins presented via Major Histocompatibility Complex (MHC) on antigen-presenting cells (APCs) are the fundamental molecular triggers for seasonal allergic diseases (PMID: 30141444). This complex is formed when APCs, such as dendritic cells, capture environmental pollen allergens, process them into immunogenic peptides, and display them on MHC Class II molecules (PMID: 25617481). Recognition of this peptide-MHC (pMHC) complex by specific T-cell receptors (TCRs) on CD4+ T cells initiates a Th2-polarized immune response, characterized by the production of IgE antibodies and subsequent mast cell degranulation (PMID: 28839087). Therapeutic interventions, primarily allergen-specific immunotherapy (AIT), target this pathway by delivering controlled doses of the allergen to induce immunological tolerance (PMID: 31005306). These therapies work by promoting the expansion of regulatory T cells (Tregs) and inducing a shift from Th2 to Th1 cytokine profiles, thereby reducing clinical symptoms upon natural allergen exposure (PMID: 24636084). Understanding the structural basis of these pMHC complexes is vital for the design of next-generation peptide vaccines that aim to provide efficacy without the risk of IgE-mediated systemic reactions (PMID: 29454138).

Other names

Allergen-MHC complexpMHCPollen peptide-HLA complexAntigen-MHC complex

Induction of T-cell anergy, promotion of regulatory T cell (Treg) differentiation, and immune deviation from Th2 to Th1 responses to induce long-term desensitization (PMID: 28839087).